damon, was looking in the manual:
apparently you can only "cold swap/warm swap" the main battery bay (std or hicap battery). Cold = turn off cpu, warm = exit all programs and goto suspend mode.
But, it seems that you can hot-swap the modular bay battery. DAMN. i shoulda gotten two of those puppies and skipped out on the regular std. battery.
As far as discharge, it drains both batteries equally... when you're at a show there's a battery level meter icon in the systray bottom right... if you hold the mouse over it it will tell you the %'age left and the approx time. I wonder if that time is different when the lid is open or closed (obviously you cant see it when it's closed, so hard to know).
I would think this laptop will run 8 hours w/ the hicap and the modular battery easily (w/ lid closed). I ran donna the buffalo last night, and the opener jim lauderdale w/ donna backing.
Total music time was like 3hrs... plus the 30-40min setbreak in between where the computer was sitting idle.
I got home and the batteries still had like 78% left.
this thing is the TITS!